Fire-alarm.



J. STEVENS.

FIRE ALARM.

APPLICATION FILED JUNE 4, 1913.

Patented July 7, 1914.

47/5/7701? L/a/m/ 5751/5445 hwuuw J Specification of Stettei's Patent.

Patented July '7, this Application filed June a, nus. .Serial no. mass.

To all whom may concern Bait known that I, Jenn Sins/Ens, a subject ofthe King of Great Britain, residing at H George street, liaunceston, in the State. of Tasmania, Commonwealth of Australia, have invented certain new and useful linrovements in FireAlarms, of which the 'ollowing is a specification.

My invention refers to an improved the alarm for the purpose of giving an alarm locally. An alarm can also be given-through an electric circuit or other means at a point not near the seat of fire.

In carrying the invention into practice, I combine with an ordinary clock-work alarm system a thermostatic arm or bar that is composed of two metals each having a different co-eihcient of expansion and so arranged in the clock-work system that when heated the expansion of the bar will release the mechanism and cause the alarm to be sounded.

A further object of the invention is to cause the clock-work mechanism, as it runs down, to close an electric circuit in connection with a tire alarm system, or to so manipulate a pull wire in order that other bells may be set going as the primary alarm runs down.

In the accompanying drawings z-l igure lsho'ws my invention in elevation. Fig, 2 is a fragmentary view of the same to illustrate the setting and testing mechanisms. Fig. 3'is a detailed sectional plan of the same. Fig. 4 illustrates in plan'the internal arrangements or the alarm, the bell being removed. Fig. 5 is a turther plan view showing the electrical contact mechanism, and Fig. 6 shows the end of the thermostatic bar and means for holding same until its expansion causes it to be released.

The clock-work mechanism is contained within a suitable holder 7 and the inner end of the spring of the same is attached to the stall 8 upon which is the main wheel 9.

Attached to the floor of 7 is a bracket to which the curved thermostatic bar 101 is secured. This bar is made of two strips of ,roetel such as brass and iron shown in Fig.

e? is upon the vibrating ld itself attached to the pallet star? 14;.

As the pallet 1-5 rocks on its staff 1+} due to the clock-work running down the hell 16 will be rung by the hammer 12. But this can only take place when the finger 11 is released from contact with 10. This will happen when the rod 10 has expanded and extended far enough for the edge of the notch orrecess its end to beyond the finger. The latter with the sounder will then vibrate to and fro in the recess 17 until the thermostat has cooled and shrunk again to about the normal, when the finger 11 will be arrested by contact with the bar.

Reterringnow .to Fig. 5 which illustrates the invention adapted to complete an electric circuit and sound outside alarms, attached to the main spring Stitfi 8, above the spring, is a pinion 18 that meshes witha quadrant 19 mounted in 7. 0n the rack 19 is aprojection 20 which as the clock-work runs down will make contact between the terminals 21 and complete the circuit.

Arranged hehind the quadrant 19 is a cradle spring member 22 which operates to prevent the rack overrunningitselt. Also attached to the quadrant 19 isa wire 23 which will be pulled inward when the clock-- worl; runs down and closes the electric cir cuit. This wire 28 may be so arranged as to release other clock-work bells in a house or to release or operate an electric switch, should it he used upon the thermostat without the contact 20. The clock-work may be wound up by turning the hell 16 which thus rotates the spindle i The thermostatic member 10 can be made to release the finger 11 at various degrees of temperature by adjusting it with the finger more or less delicately. through the hollow set screw 26 being screwed in against the bar and pushing it slightly. ill the position it will require less expansion to ree it from the finger 11 since the me; r 10 c" rves inwardly on being heated. pen the screw 2%, but not necessarily integral therewith, is an index finger 25 which is movable through an are opposite the dial 2% to indicate the approximate temperature at which the thermostat is designed or set to operate. Within the screw 26 is a push button 27 by means or": which the instrument may tested from This can be done ill time to time as to efficiency. When the instrument is let ofl prematurely by pressing the button 27 a ainst. the bar 10, the latter will return and old the finger 11 when the button is released. This thermostat may be designed as a table bell, a curtain rod ornament, 2. bedstead knob or other household ornament when a local alarm is required. It will be useful in case of fire occurring in bedrooms as the local alarm will arouse sleepers at once while in due course the alarm will be sent through the quadrant and finger 20 to the fire station.

Having described my invention what I claim as new and desire to secure by Letters Patent is 1. In a thermostatic fire alarm, the combination of clock-work mechanism having a palletstafl' and a pallet thereon; a hammer operated from the pallet stafl' a bell near the hammer; a curved bar oi two metals each having a different co-eflicient of expansion and having a recess in the endthereon; and means on the hammer normally engaging in said recess.

2. In a thermostatic fire alarm, the combination of clock-work having a" pallet stafi' and a pallet thereon; a thermostatic bar; a hammer on the stafi adapted to be engaged by the bar; a set-screw adapted to press upon the bar; an index finger onthe setscrew; and an indicator dial associated with the finger.

3. In a thermostatic fire alarm, the com-- bination of clock-work mechanism having a pallet staff having a allet thereon; a hammer operated from t e allet staff, a bell near the hammer, a curve 'bar of two metals eachhaving a different co-efficient of expansion, means for holding the hammer normally in the free end of the bar, a spur pinion on the main sprin spindle, a toothed rack gearing with thepmion and a projection on the rack which, as the clock-work runs down in sounding an alarm, will close an electric circuit, as set forth.

4. In a thermostatic fire alarm, the combination of clock-work mechanism, having a pallet stafi having a allet thereon, a hammer operated from the pallet staff, a bell near the hammer, a curved bar of two metals each having a different co-efiicient of expansion, means for holding the hammer normally in the free .end of the bar, a spur pinion on the main spring spindle, a toothed rack gearingkwith the pinionand a pull wire upon the rac 5. In a thermostatic fire alarm, the combination of an alarm, clock-work adapted when set in.motion to .sound the alarm, a thermostatic bar adapted to control said clock-work, a hollow set screw adapted to bear upon and press inward the thermostatic bar, and a push button within the set screw, as set forth.

6. In a clock-work operated fire alarm, the combination of a clock-work having a pallet and a pallet staff, a curved thermostatic bar having a recess in the free end, a hammer attached to the pallet staff of the clock-work, a finger upon the hammer adapted to come into said recess and a bell arranged near to the hammer, as herein set forth.

7. In a thermostatic fire alarm, the combination of 'a clock-work mechanism having a pallet staff and a main spring spindle, a hammer operated from the pallet staff, a bell near the hammer, a curved bar of two metals each having a diflerent co-eflicient of expansion, means for holding the hammer normally in the free end of the bar, a spur pinion onthe main-spring spindle, a toothed rack gearing with the pinion, means for limiting the movements of the rack in engagement with the pinion, and means carried by the rack for setting 1n operation additional devices.

In testimony whereof I have afiixed my signature in presence of two witnesses.

JOHN STEVENS.

Witnesses WILLIAM DUBRELLE WESTON, ALFRED HAROLD MASTERS. 

